the most spectacular night sky I’ve ever seen in recent memory… 09.13.18… rays of light stretching overhead and to the south so 3D it seemed you could touch them as they reach down overhead… pushing limits of the gear here on a moonless night limited by f.4 due to the lens choice – but the all sky view was so incredible and worth the trade off – no particularly active aurora had been predicted this night… (technically this is a “Steve” and it has been suggested this is not an aurora in some scientific circles) so goes the few weeks around the equinox.

https://www.smithsonianmag.com/smart-news/big-purple-steve-not-aurora-180970095/
STEVE — (Strong Thermal Emission Velocity Enhancements, )the name given to strange purple ribbons of light that seem to accompany auroras is not an Aurora after all, but something completely unknown, as researchers determined in only the second study ever done on the phenomena. So, if STEVE isn’t an aurora, what is the mysterious purple light? It’s hard to say. In a second study of mysterious phenomena, researchers discovered that solar particles hitting the ionosphere do not power the violet, vertical streaks.
Here is a photo of a Steve from the above link

No matter what the 1st blue & green picture posted is, it is just BEAUTUFUL!